• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1134-1137
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• 2002

To investigate the neurotoxic effect of organic chloride on cultured mouse cerebral neurons, cytotoxic effect was measured by MTT assay after cultured cerebral neurons were incubated with various concentrations of methyl mercuric chloride(MMC) for 24 hours. The protective effect of Radix Polygoni Multiflori(RPM) on MMC-induced neurotoxicity was also examined in these cultures. MMC decreased cell viability of cultured mouse cerebral neurons remarkably in a dose- and time-dependent manners. In protective effect of RPM it was remarkably effective in blocking the neuroxicity induced by MMC. From aboved the results, it is suggested that MMC induce neurotoxicity, and the herba extract, RPM is very effective in preventing MMC-induced cytotoxicity on cultured mouse cerebral neurons.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.457-460
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• 2003

It has been suggested that oxidative stress of reactive oxygen species(ROS) may play an important role in the pathogenesis of neurological disorder. The aim of this study was to elucidate the oxidative stress of glucose oxidase(GO) in the cultured mouse spinal motor neurons and the preventing effect of Benincasae Semen(BS) on ROS-induced neurotoxicity. Cytotoxic effect of GO and protective effect of BS were performed by MTT assay. 30mU/ml GO decreased cell viability in dose-and time-dependent mannner, and BS diminished GO-induced neurotoxicity in these cultures. From above the results, ROS such as GO has toxic effect, and herb extract of BS is very effective against GO-induced neurotoxicity in cultured spinal motor neurons of neonatal mouse.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.8
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• pp.555-559
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• 2003

In this paper, a new CMOS RF model for RF IC design including the capacitance effect, the skin effect, and the proximity effect between metal lines on the Si surface is proposed for tile first time for accurately predicting the RF behavior of CMOS devices. The capacitances between metal lines on the Si surface are modeled with the layout. And the skin effect is modeled with a parallel branch added in equivalent circuit of metal line. The proximity effect is modeled by adding the mutual inductance between cross-coupled inductances in the ladder circuit representation. Compared to the BSIM 3v3. the proposed RF model shows good agreements with the measured data and shows well the frequency dependent behavior of devices in GHz ranges.

• Biomedical Science Letters
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• v.25 no.1
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• pp.66-74
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• 2019

Hyperlipidemia is defined as conditions of the accumulation of lipids such as free fatty acids (FFA), triglyceride (TG), cholesterol and/or phospholipid in the bloodstream. Hyperlipidemia can cause lipid accumulation in non-adipose tissue, which is lipid-cytotoxic effects in many tissues and mediates cell dysfunction, inflammation or programmed cell death (PCD). TG is considered to be a major cause of atherosclerosis through inflammatory necrosis of vascular endothelial cells. Recently, TG have also been shown to exhibit lipid-cytotoxicity and induce PCD. Therefore, we investigated the effect of TG on the cytotoxic effect of various cell types. When exposed to TG, the cell viability of U937 monocytes and Jurkat T lymphocytes, as well as the cell viability of MCF-7, a non-immune cell, decreased in time- and dose-dependent manner. In U937 cells and Jurkat cells, caspase-9, an intrinsic apoptotic caspase, and caspase-8, an extrinsic apoptotic caspase, were increased by exposure to TG. However, in TG-treated MCF-7 cells, caspase-8 activity increased only without caspase-9 activity. In addition, the reduction of cell viability by TG was recovered when all three cell lines were treated with pan-caspase inhibitor. These results suggest that activation of apoptotic caspases by TG causes lipotoxic effect and decreases cell viability.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.246-246
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• 2016

Tungsten-nitrogen (W-N) co-doping has been known to enhance the photocatalytic activity of anatase titania nanoparticles by utilizing visible light. The doping effects are, however, largely dependent on calcination or annealing conditions, and thus, the massive production of quality-controlled photocatalysts still remains a challenge. Using density functional theory (DFT) thermodynamics and time-dependent DFT (TDDFT) computations, we investigate the atomic structures of N doping and W-N co-doping in anatase titania, as well as the effect of the thermal processing conditions. We find that W and N dopants predominantly constitute two complex structures: an N interstitial site near a Ti vacancy in the triple charge state and the simultaneous substitutions of Ti by W and the nearest O by N. The latter case induces highly localized shallow in-gap levels near the conduction band minimum (CBM) and the valence band maximum (VBM), whereas the defect complex yielded deep levels (1.9 eV above the VBM). Electronic structures suggest that substitutions of Ti by W and the nearest O by N improves the photocatalytic activity of anatase by band gap narrowing, while defective structure degrades the activity by an in-gap state-assisted electron-hole recombination, which explains the experimentally observed deep level-related photon absorption. Through the real-time propagation of TDDFT (rtp-TDDFT), we demonstrate that the presence of defective structure attracts excited electrons from the conduction band to a localized in-gap state within a much shorter time than the flat band lifetime of titania. Based on these results, we suggest that calcination under N-rich and O-poor conditions is desirable to eliminate the deep-level states to improve photocatalysis.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2979-2984
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• 2012

Recent studies have indicated a link between levels of cyclooxygenase-2 (COX-2) and development of the multidrug resistance (MDR) phenotype. The ATP-binding cassette sub-family G member 2 (ABCG2) is a major MDR-related transporter protein that is frequently overexpressed in cancer patients. In this study, we aimed to evaluate any positive correlation between COX-2 and ABCG2 gene expression using the COX-2 inducer 12-O-tetradecanoylphorbol-13-acetate (TPA) in human breast cancer cell lines. ABCG2 mRNA and protein expression was studied using real-time RT-PCR and flow cytometry, respectively. A significant increase of COX-2 mRNA expression (up to 11-fold by 4 h) was induced by TPA in MDA-MB-231 cells, this induction effect being lower in MCF-7 cells. TPA caused a considerable increase up to 9-fold in ABCG2 mRNA expression in parental MCF-7 cells, while it caused a small enhancement in ABCG2 expression up to 67 % by 4 h followed by a time-dependent decrease in ABCG2 mRNA expression in MDA-MB-231 cells. TPA treatment resulted in a slight increase of ABCG2 protein expression in MCF-7 cells, while a time-dependent decrease in ABCG2 protein expression was occurred in MDA-MB-231 cells. In conclusion, based on the observed effects of TPA in MDA-Mb-231 cells, it is proposed that TPA up-regulates ABCG2 expression in the drug sensitive MCF-7 breast cancer cell line through COX-2 unrelated pathways.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.11
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• pp.4965-4971
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• 2016

Objective: Breast cancer is global female health problem worldwide. Most of the currently used agents for breast cancer treatment have toxic side-effects. Ginseng root, an oriental medicine, has many health benefits and may exhibit direct anti-cancer properties. This study was performed to assess the effects of ginseng on breast cancer cell lines. Materials and Methods: Cytotoxicity of ginseng extract was measured by MTT assay after exposure of MDA-MB-231, MCF-10A and MCF-7 breast cancer cells to concentrations of 0.25, 0.5, 1, 1.5, 2 and 2.5 mg/well. Expression levels of p21WAF, p16INK4A, Bcl-2, Bax and P53 genes were analyzed by quantitative real time PCR. Results: The treatment resulted in inhibition of cell proliferation in a dose-and time-dependent manner. p53, p21WAF1and p16INK4A expression levels were up-regulated in ginseng treated MDA-MB-231 and MCF-7 cancer cells compared to untreated controls and in MCF-10A cells. The expression levels of Bcl2 in the MDA-MB-231 and MCF-7 cells were down-regulated. In contrast, that of Bax was significantly up-regulated. Conclusion: The results of this study revealed that ginseng may inhibit breast cancer cell growth by activation of the apoptotic pathway.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.4
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• pp.319-328
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• 2005

This paper describes a compartment dynamic model for evaluating the contamination level of kritium in agricultural plants exposed by accidentally released tritium. The present model uses a time-dependent growth equation of plant so that it can predict the effect of growth stage of plant during the exposure time. The model including atmosphere, soil and plant compartments is described by a set of nonlinear ordinary differential equations, and is able to predict time-dependent concentrations of tritium in the compartments. To validate the model, a series of exposure experiments of HTO vapor on Chinese cabbage and radish was carried out at the different growth stage of each plant. At the end of exposure, the tissue free water(TFWT) and the organically bound tritium(OBT) were measured. The measured concentrations were agreed well with model predictions.

• The Korean Journal of Pain
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• v.12 no.1
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• pp.16-20
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• 1999

Background: Tourniquet pain has important impacts on anesthesia. Tourniquet pain and accompanying cardiovascular changes are important factors that make patients in distress during anesthesia. As tourniquet pain may be modified by anesthesia, a study on the changes in the neural functions by tourniquet inflation in normal volunteers is important. Methods: Time-dependent changes in tourniquet pain, heart rate, phantom limb sensation, motor function, pain to pressure on upper extremity of 10 healthy and unpremedied volunteers were measured. Each parameter were measured every 5 minutes starting from 10 minutes before inflation to 15 minutes after deflation of tourniquet. Tourniquet was deflated when the subject felt unbearable pain (score 100 with visual analog scale). Results: Subjects manifested time-dependent pain responses to tourniquet inflation, characterized by increase in VAS, systolic and diastolic blood pressure. Mean duration of tourniquet inflation was 36.4 minutes, volunteers experienced motor paralysis at 27.6 minutes and sensory loss at 33.1 minutes. Pain to pressure decreased over time in both arms. The degree of decrease was greater in the arm on which tourniquet was applied than that in the non-applied arm. Phantom limb sensation occurred in 3 subjects. Conclusions: This study demonstrated dynamic changes in the neural functions during tourniquet inflation period. Tourniquet-induced pain and resultant hypertension occurred in all subjects. Appropriate anesthetic management is needed for the surgery using tourniquet.

• Restorative Dentistry and Endodontics
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• v.38 no.2
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• pp.73-78
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• 2013

Objectives: This study evaluated the effect of three different air-drying times on microleakage of three self-etch adhesive systems. Materials and Methods: Class I cavities were prepared for 108 extracted sound human premolars. The teeth were divided into three main groups based on three different adhesives: Opti Bond All in One (OBAO), Clearfil $S^3$ Bond (CSB), Bond Force (BF). Each main group divided into three subgroups regarding the air-drying time: without application of air stream, following the manufacturer's instruction, for 10 sec more than manufacturer's instruction. After completion of restorations, specimens were thermocycled and then connected to a fluid filtration system to evaluate microleakage. The data were statistically analyzed using two-way ANOVA and Tukey-test (${\alpha}$ = 0.05). Results: The microleakage of all adhesives decreased when the air-drying time increased from 0 sec to manufacturer's instruction (p < 0.001). The microleakage of BF reached its lowest values after increasing the drying time to 10 sec more than the manufacturer's instruction (p < 0.001). Microleakage of OBAO and CSB was significantly lower compared to BF in all three drying time (p < 0.001). Conclusions: Increasing in air-drying time of adhesive layer in one-step selfetch adhesives caused reduction of microleakage, but the amount of this reduction may be dependent on the adhesive components of self-etch adhesives.